The German patent application DE 10 201 060 282 discloses a method for computer-based communication. The computer-based communication, by which at least two users exchange messages and are shown images of the respectively other user, in particular takes place via the internet. The degree of recognition of the images changes during the communication process. After a certain number of exchanged messages, the recognizability is larger than 0% and smaller than 100%. The degree of getting to know each other or respectively the degree of building trust regulates the degree of recognizability. The two users are connected by means of a server. This system cannot guarantee a secure communication between mobile end devices or data processing units. Alphanumeric and/or image data sets cannot be sent in such a way that a security against access of other, non-authorized users is guaranteed.
U.S. Pat. No. 8,744,143 describes a method by which a protection of the privacy of uploaded images is possible. Thereunto a person is identified in a recorded image. A part of the image, which shows the person, is shown blurred, to avoid a recognizability of the person. The person is provided with a tag. The blurring is only removed, if a permission is given to the friend (respectively the other user). The permission can be achieved, e.g., by sending a message to the not recognizable person, provided with the tag. After the permission, other friends or the public of the social network can see the image and download it. If no permission is sent back, the image stays blurred.
The U.S. patent application US 2012/0219053 discloses a device for transmitting data, wherein the transmission occurs by means of an encrypted image. Thereunto a communication system with a first unit and a second unit is disclosed. The first unit comprises a storage medium, which stores the data, which are to be transmitted to the second unit. The encoded image to be transmitted can be shown on a display of the first unit. The camera of the second unit is directed to the display of the first unit in order to take a picture of the depicted image. The second unit sends a status report to the first unit, like e.g. the success of decoding. This method of transmission results in high data security, but the first and second unit have to be aligned to each other.
The U.S. patent application US 2014/0258707 A1 discloses a secure communication system between mobile devices. A direct communication between a sending mobile device and a receiving mobile device is described. The sending device requests a public key from the receiving device. The file to be transmitted is encrypted with the public key. The encrypted file can be transmitted as attachment of a message. The receiving device can decrypt the file with a private key and the public key, received before. Even if a third mobile device intercepts the encrypted file and the public key, the private key for decryption is missing at the third device.
The U.S. patent application US 2011/0149014 A1 discloses a communication system and a method in order to protect privacy. The mobile phone can be used during a communication to protect the privacy of the person being called. The mobile phone has a special unit for this purpose. Images and videos can be recorded by the camera. The program installed in the mobile phone can be used for protecting privacy during the video call. When the mobile phone is called, a dialogue box is generated on the display, by which a video transmission or the transmission of an image, stored in the storage medium, is permitted. An obfuscation of the transmitted alphanumeric and/or image data is not provided.
The British patent application GB 25 12 140 A discloses a system and a method for transmitting messages. A secure method is disclosed to determine if a screenshot was made by a receiver of a message. Furthermore it is prevented that screenshots can be made by an external camera. To this end, the image can for example be provided with a watermark. Thus the unauthorized recording of screenshots, and therefore their distribution, are more difficult. But it is not possible to transmit in this way alphanumeric and/or image data securely and in a manner that they are not readable by every third party.
The Japanese patent application JP 2014/89625 discloses a method for searching a person under regard of privacy. With the help of a search string, faces of persons can be searched for, who are shown in images on the internet and who have allowed this. In the case of persons who did not allow this, their faces are garbled to protect privacy.
The international patent application WO 2013/160539 discloses a method and a system to protect privacy in images. For this purpose, the first setting of a user relating to privacy is saved. Due to the first setting, the face of the user is recognized. The second setting is sent to a second user of a second mobile device. After a certain time, part of the image is shown blurred. An immediate transmission of alphanumeric and/or image data sets, made unrecognizable at transmission, is not disclosed here.
The U.S. Pat. No. 8,914,752 discloses a method for sending messages. The sent messages are deleted automatically after a certain period of time after first reading. Touching the display of the mobile device launches a timer, which provides the period of time. After expiry of the period of time, the transmitted message is deleted.
The international patent application WO 2014/194262 discloses a server with a module for messages. A processor executes instructions to maintain a message between a first user and a second user. Each item in the message is deleted after a predetermined time, unless a different instruction is given.
The U.S. Pat. No. 8,909,725 B1 reveals a server module, which determines push-criteria. Due to the push-criteria, objects (images with text, images or videos) are sent to one or more edge-servers, so that the request of a user is satisfied. Deletion criteria can also be defined, like for example that after viewing the object once, it gets deleted.
The U.S. patent application US 2013/0305383 A1 discloses a system and method to protect the privacy of multi-media data, uploaded on webpages by users. A server, on which an internet data protection service is implemented, receives a media element of a user of the social network. The media element (e.g. image) is encrypted. An agreement determines, who can view the media element. The encrypted media elements are stored securely in a cloud. The encrypted images are protected by means of DRM-protection and access control. A user with access rights can download the image and it can be viewed after the decryption.
Neither WhatsApp, facebook, Skype nor Snapchat offer a possibility to send alphanumeric and/or image data sets in such a way that a third party cannot recognize the content of the data sets. Only with authorization by the sender the receiver can view the alphanumeric and/or image data set on his data processing unit.